* {
  box-sizing: border-box;
  font-family: system-ui, -apple-system, BlinkMacSystemFont, sans-serif;
}

body {
  margin: 0;
  min-height: 100vh;
  background: #f6f7fb;
  display: flex;
  flex-direction: column;
  align-items: center;
}

.card {
  background: #ffffff;
  width: 100%;
  max-width: 420px;
  margin-top: 60px;
  padding: 24px;
  border-radius: 14px;
  box-shadow: 0 12px 30px rgba(0,0,0,0.08);
  text-align: center;
}

h1 {
  margin: 0 0 6px;
  font-size: 24px;
}

.subtitle {
  margin: 0 0 20px;
  color: #666;
  font-size: 14px;
}

input {
  width: 100%;
  padding: 12px 14px;
  font-size: 15px;
  border-radius: 8px;
  border: 1px solid #ddd;
  margin-bottom: 12px;
}

input:focus {
  outline: none;
  border-color: #2563eb;
}

button {
  width: 100%;
  padding: 12px;
  font-size: 15px;
  border-radius: 8px;
  border: none;
  cursor: pointer;
  margin-top: 6px;
}

#generateBtn {
  background: #2563eb;
  color: #fff;
}

#generateBtn:hover {
  background: #1d4ed8;
}

#downloadBtn {
  background: #10b981;
  color: #fff;
}

#downloadBtn:disabled {
  background: #cbd5e1;
  cursor: not-allowed;
}

#qr-wrapper {
  display: flex;
  justify-content: center;
  align-items: center;
  margin: 20px 0;
  min-height: 180px;
}

.ad {
  width: 100%;
  min-height: 60px;
  margin: 14px 0;
  background: transparent;
}

footer {
  margin: 40px 0 20px;
  font-size: 13px;
  color: #888;
}